Substrates called "ski waxes" which improve gliding properties of the ski by lowering the friction coefficients between the ski sole and the snow surface are well known in the field of skiing.
As a rule the sole of any ski consists of a very high molecular weight polyethylene and there are several reasons why the ski waxes are applied to the ski sole, namely:
1. To reduce or eliminate surface roughness of the sole and irregularities of the sole in such a manner that the sole is rendered nearly perfectly smooth and even and, therefore, resistance due to mechanical friction of the gliding surface is reduced.
2. To lower the surface tension so that adhesion of the gliding surface to the snow surface is reduced due to the lower interfacial energy of a chemical nature between the two surfaces.
3. To act as an actual lubricant, liquid or solid depending on the types of wax used, between the ski sole and the snow surface.
The first ski waxes used in the field of snow skiing, and the ones used most commonly today, consist of various paraffins. The waxes differ from one another in several ways which include differences in:
Molecular weight distribution curves of their components PA1 Number of branching or cross-link density PA1 Possible oil contents PA1 a) sprayable paraffin can be distributed more uniformly or evenly over the sole while the amounts of the paraffin being consumed is reduced; PA1 b) paraffins of high molecular weight can be utilized in sprayable paraffin solutions which could not be previously applied in a powder form solely due to its high molecular weight. PA1 a) they contain, in many cases, toxic substances such as chlorinated or aromatic solvents, and, in many cases, are flammable; PA1 b) after application to a ski sole, and after the majority of the solvent has evaporated part of the solvent still remains trapped within the paraffin modifying the characteristics of the latter.
Degree of crystallization and melting point, which usually depend on the three characteristics listed above.
Since 1985, in addition to paraffin ski waxes described above, fluorinated ski waxes, or so-called "fluorinated waxes," became available. In fluorinated waxes hydrogen atoms of the paraffin are completely substituted with fluorine atoms.
These fluorinated waxes exhibit extremely low surface tension which, in turn, results in a lower coefficient of friction of the ski on the snow.
These waxes, however, have some disadvantages such as high vapor pressure in conjunction with a high melting point and immiscibility with or insolubility in hydrogenated paraffins.
For increasing the range of applicability of these waxes, over the past few years waxes with mixed chains that serve as compatibilizers between the fluorinated and hydrogenated waxes have been developed. These compatibilizing waxes comprise chains that are partially hydrogenated and partially fluorinated. Addition of hydrogenated paraffins to fluorinated waxes improves the characteristics of the fluorinated waxes by lowering their volatility as well as the melting point.
One of the most important characteristics determining the quality of a ski wax is its ability to be applied to a ski sole without impairing the physico-mechanical properties of the sole.
Thus, a hydrogenated paraffin can be effectively applied to a ski sole as long as its melting point is below 105.degree. C. to 110.degree. C.
If, however, the melting temperature of the paraffin is above 118.degree. C. to 120.degree. C., the ski sole the paraffin is applied onto and which absorbs such paraffin may separate from the ski or the surface of the sole may be damaged so as to impair the original characteristics of the sole.
Recently sprayable paraffins or paraffin solutions have been marketed which present several advantages over the conventional paraffins as follows:
These sprayable solutions currently available on the market, however, present the following disadvantages:
Up to now, no fluorinated wax in sprayable form has been available or disclosed in the literature, because the fluorinated waxes, i.e containing completely fluorinated or perfluoronated chains, are not soluble in any hydrogenated organic solvent.
The present invention provides fluorinated waxes that can be applied as sprays or aerosols and eliminate the above-mentioned disadvantages of the known sprayable solutions containing paraffins or paraffin waxes.